Wilson Alexia 2 lacking some bass

I have had Alexia 2s and now Alexia Vs. I agree with others here. The lack of bass is usually caused by the location in the room. One of the key factors is whether the port is reinforced by the wall behind the speakers. Move them closer to the wall and see what happens. You should be able to attain excellent bass with your system. Don't change your amps.

Set your speakers for best imaging get some Rel 812's

You may be sitting in a null. I had a room 15 x 20 x 8 and needed to move my seat back until the room response flattened out from my ear position. I did this 6 inches at a time with the laptop and mic until it was optimized. It was not at the 62% back rule of thumb. Roughly your 15 ft has a resonant freq of 37 hz and your 8 ft ceiling is 70. That is a problem right away. Your 20 feet is about 28 hz. That room had Sasha One's.

Today's room has Alexia One's. I had to bass trap the heck out of it to make it flatter. See my virtual room in Tennessee. The Sasha room is also in the system under Kentucky.

I think this is readily solvable. Your gear is stellar.

Suggest you try a good preamplifier in your system. My Bartok sounds great until I put the Conrad-Johnson ART88 pre back in the system. A much fuller more complete sound stage. Most, including now even Paul McGowan who fought the concept of a preamplifier, seem to find a more complete presentation with a pre in the system.

I also have the Alexia 2's.  I run it with Esoteric electronics.  The Alexia's bass is awesome is the word that comes to mind.  It's the sitting position that is the problem.  I found moving the sitting a couple of feet closer or further away from the speakers are areas of bass nulls.  Try it, move around your sitting position and see for yourself.

I used to own Alexia 1's until moving up to Alexx V.  I tried adding subs to the Alexia's and it did not do much. Ultimately I think speaker position is key.

@OP. Congratulations - very nice system. Wilson's bass is somewhat overdamped and some people don't like that particular characteristic - personally I do. That is the subjective impression of the bass as opposed to the measured frequency response the speaker is actually delivering. It would be worth trying a pair of Shunyata Typhon T30's which should bring more impact and dynamics in the bass. Also, despite what DCS say, I prefer the Rossini via a dedicated preamp, as opposed to driving power amps directly, which is what I assume you are doing.

Forgot to mention the obvious. Reflections act like tone controls. Excess refelctions will make a speaker sound bright. Tame the mid/treble reflections and often bass will emerge like a galleon at low tide.  Don't forget the ceiling, especially between listener and speaker.

I had a pair of Wilson Alexia’s and upgraded to the Alexia V.  Additionally, I have a pair of Rel S812’s next to each Alexia. I would check the distance from your back wall to the speaker and see if moving it around helps.  Are tour speakers tied in? That will also help with bass.  I added the Rel s812’s to ease the lower end on Alexia’s.  Having had Nagra equipment and demo’d before my final purchase I don’t think it could possible be the amps. Those are some of the finest products ever made.  Also, note that in Nagra uses Wilson speakers in many demos and at many of their shares so the components are a good match.  I think you need to demo a pre amp before doing anything else.  I’m sure your dealer would let you demo one to see if it fits in your system. 

I would add 2 Rel subwoofers like the S 510 or the S 812. I just added 2x S 500 with my Shindo Masseto and Montille amp and Fleetwood Deville SQ. Wish did it before, it is really a match made in heaven. Perfect bass , better coherence and live sounding.You won’t regret it, believe me, will take your system to another level.

I owned Alexia2 for almost one year and just traded in for AlexiaV this week. In my experience Wilsons are never lack of bass response (not sure you meant 40hz deep bass or 80-100hz mid bass, and not sure you meant lack of bass volume or dynamics ?)  also how large is your listening area that the amp+speakers can fill with enough power ? 

I would try to move the speakers 1/4inch at a time, towards the front wall and see if it helps. Another thing I tried is to take away the grilles of bass drivers and it should give you 5% more dynamics or punch feel. 
 

I am not familiar with the preamp you are using , but another way to try is to adjust the gain on your preamp and see if that helps. 

@greenspyder718, does the minor low-end lack you describe show up throughout the room, or only in the listening position? 

Is your 20 x 15 foot room open into any other rooms?

Can you describe approximately where the speakers are relative to the nearby walls? 

Thanks!

Great system.  Maybe the Alexa’s are to far from the front wall?.

Just a thought.

I’ve got almost the same setup with Alexia 2 and Rossini Apex but with Boulder preamp and amp. The bass is terrific. In fact, I replaced B&W 802d3 which were anemic. The Alexia has amazing bass. 

Two possibilities. One already mentioned, position in room. There are spots where base is poor or even almost doesn't exist. This is purely a factor of room dimensions and speaker position  in the room. Unfortunately the position for best mids and/or imaging are often not good positions for deep bass.

Second what do you base the lack of bass on? Is it measurement or listening to sources or even test records? How loud do you listen. Our ears roll off in the bass in relation to loudness. Our ears are flat around 100 dB(way too loud for ear health). Below that level the bass loss is because of ear roll off. And the roll off is extreme. I'm lazy and don't feel like looking it up but I recall 20 Hz being over around 15 dB at 80dB level(still loud for long term listening). Before the adoption of minimal controls we had things like bass controls and loudness controls to try to compensate for our ear response.

Check out hte AM Acoustics room simulator.  You input your dimensions, and it helps you locate your speakers and listening area away from nodes/antinodes.

Like westcoastaudiophile I see no preamplifier. If you are running straight from the DAC to the monos that could be your problem. Maybe look for a high end pre to match what is otherwise an incredibly good system, even if I don't like Wilson speakers.

Congrats on this excellent system!

As others mentioned, run a frequency test. These speakers should have solid bass. 

Wilson recommendation in a manual for my Sabrina is speaker to listening position should be 1.1 to 1.2 times the distance between speakers (measured between center of tweeters).  That works for me but no two rooms are alike. 
Experiment and see. Walk around the room while test tone is playing to see if you are dealing with a listening position located in a null point

+ 1 @onhwy61 and once determined then play around with speaker positioning.

The minor lack of low end response?  Compared to what?  Using a test frequency track can help pinpoint the exact frequencies involved.  That should be determined before any solution can be attempted.

Placement is key, but the best bass response might not be the ideal placement for the mids and highs. A sub, or 2 under 50Hz with their own volume control might be the ticket for that last octave to really kick in.

I’m wondering if the amps may not be the ideal match or if further adjustments to the speaker placement could help resolve this.

You could keep changing amps and placement until blue in the face or.....the simpler solution is to get a pair of subs....

@greenspyder718 how do you drive mono-amps, what is your preamp? also, what is sound level you think bass is lacking? 

Well, for one, all Wilson speakers are well known for having some of the best bass and dynamics in the business. So, right off the bat, we can eliminate the speakers for possibly being the issue. I have Revel Salon 2 speakers, which have the same kind of great bass that the Wilson speakers have, and wherever I position them, the bass is still there, so I don’t believe that speaker placement is the real issue here either. I believe that your lack of bass issue most likely stems from either your amplification or your cabling. All you can do now is experimentation with different cables and amps until you get the kind of bass that the speakers are capable of. Happy listening.

Wow, beautiful system you have assembled. All broken in? Correct? A system like that at least 500 hours… but the bass should be real close after 200. It would be of great help to see photos. You can easily post them by creating a virtual system. You can see mine. The venue is critical and it is not easy to describe fully in words.

I would say with great certainty speaker placement. It typically takes me a year to get mine optimized. When I am concerned about bass. I take off the spikes and put sliders under the speakers. Number one will be distance to wall behind and sidewalls. Once you are sure this is right… the toe in can increase the treble… tipping the overall balance.

Finally if all that leaves you a bit uninspired… is there a chance the system is a little too polite? dCs is very resrained and a bit well, not cold… but not warm.

Very well sorted out system, congrats.  The setup guides are just starting points and the sound you hear is totally dependent on the nuances our your listening room.  Every little detail of the room matters.  Perhaps your listening position is in a node or partial node where you're getting a little bass dip.  It took me months to be fully satisfied with my speaker positioning.  Keep in mind that anything new in your system needs adequate time to run in.  Reposition your speakers or listening spot in small increments and be patient.  It would be helpful for the community to see a pic of your listening room and maybe have some other thoughts.  Good luck and cheers.